The checklist of stuff to take with you to a car boot sale could easily be endless: warm clothing, a shopping list, or a list of prices you want to sell your stuff for, etc…

So what do we think is the most important thing to take with you?

For eager shoppers, we reckon you most need bags. And preferably, bags that can roll up and hide away in your pocket or handbag – then a seller can’t try and fob you off with a higher price because they know you really want to be buying! We recommend cool and environmentally-friendly tote bags – though supermarket plastic bags are just as efficient and usually around the house.

For sellers, we think you need to take care of yourself on what can be a long day. Take a thermos! Whether it’s hot soup or warm tea or coffee, you’ll be glad of a bit of comfort on a cold day. If it happens to be hot and sunny – not always guaranteed in rainy Britain – then pop a bottle of water or juice in the freezer the night before your car boot sale. It’ll be a block of ice when you take it out in the morning, but will keep you cool throughout the day as it defrosts.

For sellers and shoppers alike, take lots of change! Coins are your friend at a car boot sale – you won’t be popular if you try to pay your 50p entry with a £20 note!

Our map shows that London car boot sales don’t open earlier than 7am. But, if you like your lie-ins, you can still have a few extra hours in bed and attend a car boot, with lunchtime openings across the city.

Some sales might also have a rule that sellers cannot leave the site before a certain time.

The earlier the sale begins, the more hardcore your bargain hunters tend to be. They will be looking for collectibles, such as ceramics and glassware, and will want low, competitive prices. Your buyers might even be professional traders, looking for items to ‘upsell’ for their own profits.

Sales that start mid-morning or later are more likely to attract passers-by or the more casual browser, looking for inspiration and to be pleasantly surprised. These sales would be perfect for trying to get good prices for your stylish clothing.

If you take food to sell, target your audience’s appetites: you’ll probably find that sugary cupcakes aren’t too popular at 7am. For early mornings, try savoury items such as pasties and sausage rolls, or even a bowl of fresh fruit. We’ve spotted at least one enterprising stallholder selling individually-wrapped slices of cold pizza – perfect for staving off a tired head after a late night.

As for the aforementioned cupcakes: they’re becoming near-ubiquitous among younger sellers at car boot sales. They look pretty, but you’ll need to be a decorating whiz to make yours stand out. You could try food colouring in your icing, or edible cake toppers. You could also cater to the more traditional cake lover with nice thick slabs of versatile loaf cake, in whatever flavours you prefer.

Still, no matter the time you turn up, an important factor in the success of your day will always be the weather. Soggy car boot sales tend to be quieter car boot sales. You might feel it’s not worth turning out on a rainy day to sell, and if you’re a buyer this could be the opportunity to get lower prices from sellers eager to get home.

In the second of two posts exploring the variation in entrance fees at car boots across London, we look at entrance fees for buyers.

Map showing how entrance fees vary across London

Our map shows that the cost of entrance for buyers in London is usually no more than £1.

12 of the city’s car boot sales are free for buyers to enter, with a further eight costing only 50 pence.

This is significantly cheaper than the average entry fee for sellers. Perhaps car boot organisers are encouraging sellers to pay high pitch fees by luring in lots of buyers.

This is a reflection of the times. With the country in recession people are more likely to want to make money as a seller than spend it as a buyer.

Where as in central London there is a lot of variation between buyer entrance prices, the car boots charging an entrance fee of 50 pence are mainly grouped together in West London, with the free car boots grouped closely together in East London. The car boot organisers are adapting to take on their competition, knowing that buyers will go to their cheaper direct competitors.

In such areas, getting rid of entrance fees for buyers may mean higher overall profits. This is because car boot sales which only charge 50 pence per buyer can only make £50 per 100 buyers.